The combination of shit and lint that collects in a mans ass crack (usually hairy) after a particularly stressful, physically exherting, or otherwise harrowing day. (Could also be the result of wearing new underwear for the first time that shed alot of lint)
Typically, shint is removed in the shower, and its discovery is usually accompanied by a vocalization of disgust by the victim.

After wearing a new pair of underwear on a particularly hot day, Tony – while showering – discovered a mass of shint tangled in his ass hair, and removed it with a noise of disapproval.